A current focus for the therapeutic treatment of cancer involves the knockdown of genes. VEGFR-2 is responsible for the cell proliferation, survival, and migration of cells during angiogenesis or the formation of new blood vessels. Angiogenesis is required for the survival and metastasis of tumors. Gene transfer, both siRNA and adenoviral vector (AdV), is currently limited both in vitro and in vivo. Encapsulation of shRNA containg AdV within our developed polymeric nanoparticle (NP) vehicle will overcome problems such as limited blood stability and intracellular delivery. Our vehicle has been previously demonstrated to deliver AdV vectors containing a gene for luciferase, both in vitro and in vivo, which indicates it is an excellent choice for delivering therapeutic AdV vectors such as for VEGFR-2. Additionally, use of our delivery vehicle will allow the facile modification to include a peptide targeting agent to increase the therapeutic effect to the targeted tissue while decreasing the effect to normal tissues relative to traditional methods. While there are current clinical trails for the use of VEGF antibodies for tumor suppression, there are no targeting strategies being investigated. This research will be undertaken with the following specific aims: 1) Nanoparticle formulation - Integrate E-c(RGDyK)2 targeting and an shRNA-containing AdV vector to silence VEGFR-2 (kdr/flt-1) into our established polymeric NP vehicle, 2) In vitro efficacy - Determine the utility of the delivery motif for targeting and gene transfer, and 3) In vivo effectiveness - Establish the efficacy of the NPs on angiogenic neovascularization of tumors and sponge implants in mice. Methods will include typical in vitro and in vivo techniques such as PCR, immunoblots, and ELISA as well as cell proliferation, migration, and1 VEGFR-2 downstream assays. NP in vitro binding assays and in vivo biodistribution will be employed to determine the efficacy of the NP targeting. This research is relevant to public health as it's purpose is to develop more effective cancer treatment methods which decreases the distress on normal tissues common to most traditional methods.